Tag: MESSENGER

MESSENGER is a spacecraft that’s been orbiting Mercury since early 2011, sending back to Earth huge amounts of data about the tiny planet, including incredible high-resolution close-up images. It’s an amazing mission…

… but I wonder what kind of Mickey Mouse outfit would put up this kind of image for display?

[Click to enmusculate.]

Well, at least I know to whom NASA can turn if the current budget cuts get through Congress.

Emily Lakdawalla is a scientist, science journalist, and tireless advocate for space exploration. She also does handcrafts, and recently asked me for my mailing address. Hmmm… I thought. This’ll be good.

And I was right! Here’s what she sent me:

How cool is that? It’s a satellite model made with plastic canvas. That’s a plastic mesh you can cut to size, then stitch yarn in and out of the holes to cover it. I did a live video chat with Emily when Phobos-GRUNT re-entered, and she lamented my not having a good model of a satellite to use for demos. So she made me this one. And look how she signed the letter! I hope you recognize the little guy in her doodle.

I’ll add that Emily scolded me that this is not crochet since you don’t use a crochet hook. However, the title was too much fun to resist. By the time you read this I’ll be at SpaceFestIV; Emily will be there too. I hope she’ll forgive me.

But either way, I know have this awesome little model to use for the next time I do a live video chat. Thanks, Em!

I know I just posted a MESSENGER photo of craters, but this one is different and spectacular enough that I figure, why not? I love a big, splashy, wide-angle shot of a rayed crater! So here’s the lovely, 80-km wide impact crater Debussy on the surface of Mercury:

[Click to haphaestenate.]

Craters make rays when the ejected material blasted out forms long plumes which fall across the surface. On airless worlds, those trajectories are ballistic, heading straight out from the center of the impact. Deeper material tends to be a lighter shade than surface material, so the interior of the crater and the rays are lighter than surrounding surface stuff. You can also see what’s called the apron, the layer of material that falls immediately around the crater, surrounding it (that’s more clear in an earlier image of the crater looking more straight down on it).

Rayed craters are common (even on our Moon; take a look at Tycho!), and usually indicate the impact was recent (geologically), since the rays eventually get eroded by the solar wind, cosmic rays, and subsequent meteorite impacts. Debussy is therefore one of the younger features on Mercury. It still has that youthful shine.

The MESSENGER spacecraft, orbiting Mercury for nearly a year now, took this pretty nifty shot of the tiniest planet’s south polar region, showing deep, dark craters in the Goethe basin:

This region is about 300 km (180 miles) from the true south pole of the planet. On Earth that might be a cold spot, but on Mercury, cold spots are hard to come by.

… however, see how dark those craters are? Since they’re near the pole, the Sun never gets far above the horizon for them, and the crater floors are shrouded in perpetual darkness. That does make them cold! Well below the freezing point of water, it’s thought. Interestingly, radar observations of Mercury have indicated something in the crater floors is highly reflective, and water ice fits that bill. It’s not at all confirmed, but it’s entirely possible Mercury — a planet hot enough in the open Sun where zinc can exist as liquid lakes on the surface — might have frozen lakes of ice locked in crater bottoms near its poles!

While gazing idly at this picture, another thought popped into my head. Read More

We live in an era of wonder, where people send robots to other worlds and view them close up. These machines get bathed in radiation, searing heat, bitter cold, suffocating vacuum, and they keep running. Moreover, they send their data back digitally, which can then be stored in a database and, if permissions are given, accessed by the public. And a subset of that public is educated in the ways of digital media, able to stitch together pictures, carefully aligning them, balancing them, coordinating borders and overlap regions.

The result? This:

Yegads. That is Mercury as seen by the MESSENGER spacecraft in 2008, as it flew by the planet for the first time. It would do so again before finally entering orbit in March 2011. But as it left the smallest planet, it snapped a series of wide angle and high-resolution images.

Gordon Ugarkovic is a Croatian software developer. He’s also an amateur image processor… for a sufficiently wide definition of "amateur". He takes space images and works his prowess on them, creating dramatic and beautiful images like this one of Mercury.

Click the picture to embiggen it, or you can also download a vast 5000 x 5000 pixel version that is, frankly, spectacular. Gordon used over 30 of the high-res frames from MESSENGER’s Narrow Angle Camera to make this mosaic, and then used images from the Wide Angle Camera to balance the color.

The 25 megapixel image is nothing short of amazing. Scrolling across it is like flying across the planet. I see features there I hadn’t noticed before, like a pale dark streak just south of Mercury’s equator, sharp cliffs called scarps that litter the surface, craters with bright rays of ejected material streaming out of them. It’s breathtaking.

Gordon has also done images of Saturn, Jupiter, and moons galore. You can follow his work at the Unmanned Spaceflight forum, or peruse his Flickr stream. But be warned: better have a lot of time handy. You’ll be spending it there.

Image used with permission. Tip o’ the heat shield to Dan Durda for tipping me off to the picture.

When an asteroid or comet impacts a planet, the explosion ejects huge amounts of material, sending it flying in all directions. But there are also plumes of material, long fingers of rock and dust that stream out as well. The boulders and such inside this plume then fall back to the ground, making linear chains of secondary craters. We see lots of these on our Moon, moons in the outer solar system, and Mercury, too.

If these features are long enough, it’s inevitable two chains from two different primary craters would cross somewhere. And it turns out this has been seen… but where?

This MESSENGER image of Mercury shows exactly that: two crater chains from two separate impacts crossing over each other (and a third, shorter chain is at the bottom, too). They’re almost exactly perpendicular to each other, which is cool, and the intersection happens to lie in a big, shallow crater about 120 km (72 miles) across that fills this image. Unfortunately, MESSENGER hasn’t been orbiting Mercury long enough to have surveyed the whole planet yet, so I wasn’t able to find the source craters of these two chains.

Interestingly, both chains have elongated craters at their ends, one on the upper left and the other at the top. That indicates a very low-angle impact; anything hitting the ground from an angle above about 10° tends to make a circular crater. However, the one on the left appears to be right on the big crater’s rim, so the elongation may be due to the ground angle changing. The other may be coincidence; both are far too small to have been the source craters for the chains.

I’m not sure there’s any real scientific value in knowing these crater chains intersect or examining the intersection in detail. Still. They’re fun to look at, fun to explore, and they’re just seriously nifty.

NASA has just released more images of Mercury as seen by the MESSENGER spacecraft, and they’re pretty cool:

This first one is something of a repeat, showing the same region as the picture they released yesterday, but now it’s in color! Mercury is not exactly the most beautifully hued planet, but it does have some color to it. This composite was taken in the infrared (shown red in the image), red (shown as green in the image) and blue (shown as blue), and has a maximum resolution of about 2.7 kilometers (1.6 miles) per pixel. While most of the surface looks gray, look again: some of the craters do show subtle color variations. This is most likely due to the material excavated on impact — composition, particle size, and other factors change the way these features reflect light. This image only uses three colors, but the wide angle camera has eight 11 filters, which will allow planetary scientists to map the planet very effectively and learn about the composition and history of the surface.Read More

The picture is dominated by the crater Debussy (named after the composer, who wrote "Clair de Lune", apropos of nothing, I suppose*), an impact crater about 80 kilometers (50 miles) across. It’s a rayed crater, with plumes of ejecta leaving those long, linear features across the planet.

This image is the first ever returned from a spacecraft orbiting Mercury, but MESSENGER has already taken hundreds more, and thousands are planned during this commissioning phase (when the various instruments and spacecraft are checked out). The real science observations begin April 4.

Tomorrow, NASA will have a press conference and more images. I’ll have more info and more amazing pictures from Mercury to show you then!

Just a quick note to y’all, since I’m in the middle of about eight things all demanding my full attention: the MESSENGER spacecraft will enter orbit around Mercury tonight at 9:00 p.m. EDT, after a tortuous 7-year journey. Once safely circling the planet, engineers will be focusing on making sure the probe is safe and sound, so it’ll be a while (days) before we start getting images.

I’m quite sure my pal Emily Lakdawalla will be poised for attack on every tidbit of news that comes in, so follow her on Twitter and on her blog at the Planetary Society.

On March 17, just a month from now, NASA’s MESSENGER probe is scheduled to enter orbit around Mercury, the smallest planet in the solar system. No other mission from Earth has ever done this, and for the first time we’ll get high-resolution maps of the entire globe.

On its way down, the spacecraft was commanded to turn around and look outward, toward space. It took a series of images of what it saw… this astonishing family portrait of the solar system:

Click it to ensolarsystemate it and see it in more detail. When you do you’ll see the five classical planets in our system, as well as the Earth and Moon. Uranus and Neptune are there, but too faint to see, unfortunately, but still, this is an interesting picture. In November 2010, when these pictures were taken, Mercury was still nothing more than a dot. In fact, all the planets as barely more than dots, a reminder that this probe is well away from home and nowhere near any solid ground.

I like very much the images of Venus and the Earth. Venus is technically the closest planet to MESSENGER besides Mercury, though it depends on where the planets are in their orbits. It’s extremely bright as seen from the spacecraft, since MESSENGER is inside the orbit of Venus: the planet is therefore close to being full (like the full Moon) and reflects a lot of light back to the cameras.

And the Earth is accompanied by the Moon! That always amazed me. I’m so used to seeing pictures of just the Earth from space that it’s easy to forget that the Moon travels along with us. An important reminder in this picture is just how far the Moon is from us; 400,000 km is over 100 times the Moon’s size, so it appears to be a dot located well away from its home planet. If you wanted to make a scale model of it, a good way would be to use a golf ball to be Earth, and a marble located a meter away to be the Moon. That really brings home — ironically! — how small and distant our Moon is.

If you look to Jupiter you can see it has a couple of moons near it as well. The four moons spotted by Galileo 400 years ago are pretty big; Ganymede is actually about the same size as Mercury itself! Were Jupiter not there, Ganymede might be considered a planet on its own.

I smiled when I saw the section of the picture between Jupiter and Mars — that fuzzy glow is the Milky Way itself! The split down the middle is a dead giveaway; that’s caused by dust located in the disk of our galaxy. That section of the sky looks toward the center of our galaxy in the direction of the constellations Scorpius and Sagittarius.